This application generally relates to ultrasonic transducers. The application further relates to ultrasonic transducers used for medical imaging.
A trade-off in medical ultrasound imaging is depth of penetration and spatial resolution. Higher ultrasound imaging frequencies enable higher spatial resolution at the expense of depth of penetration. Lower ultrasound imaging frequencies enable deeper penetration at the expense of spatial resolution. It would be useful if a single ultrasound imaging device was able to image across a broad range of frequencies in order to operate at a higher frequency for better spatial resolution and at a lower frequency for deeper penetration.
Broad bandwidth ultrasound imaging devices may include use of high sensitivity materials (e.g., single crystal piezoelectric composites), use of multiple matching layers, use of multiple transducers, and use of multiple devices. These approaches can be expensive and be difficult to implement from a manufacturing perspective, particularly for small, single-use, high-frequency ultrasound devices that are used in relatively high volumes (e.g., intravascular ultrasound catheters).
It would be advantageous to have an ultrasound transducer structure and corresponding manufacturing process that enables broadband imaging performance for small, single-use, high-frequency ultrasound devices. It would be further advantageous if the transducer is cost effective and easy to manufacture.